On Mon, Apr 06, 2026 at 05:11:30PM -0400, Andres Freund wrote: > heap_insert() > ->CacheInvalidateHeapTuple() > ->CacheInvalidateHeapTupleCommon() > ->AssertCouldGetRelation() > not being cheap and running a *lot*. > > Admittedly it's way worse if you build with -O0, which I tend to do to make > debugging easier. > > In that config, the assert single-handled increases the time for a repack by > 35% or so. > > > Noah, is there any reason we need to do the AssertCouldGetRelation() before > the !IsCatalogRelation(relation)? Given that the goal is to make > RelationGetRelid() safe, it doesn't seem there is?
By running AssertCouldGetRelation() during every INSERT statement, this detects cases that would be unsafe when the target of the INSERT happens to be a system catalog. Little of our INSERT/UPDATE coverage targets a system catalog. Hence, the current position is better for detection. I wonder if this got slower in v19. In v14-v18, the assert's cost is proportional to the number of held lwlocks, often 0 or 1. In v19, it's proportional to PrivateRefCountHash cardinality.
